Systems for the direct control of steam extracted from dedicated adjustable bleeding from a conventional steam power plants operated on fossil fuels are known.
The main disadvantage of using such known systems at the NPP turbines is the impossibility of observing the conditions imposed by the turbine and the turbine steam generator and reactor assembly.
Another disadvantage of the use of a direct control element for the steam flow with nonadjustable bleeding is that it implies large inconveniences due to large sizes, low sensitivity of the control element and low reliability, elements which do not meet the safety and quality conditions required by NPP high power units.